1. Field of the Invention
The present invention relates to a projector type vehicle headlamp unit using a light emitting diode (LED) as a light source, which can form a headlamp by assembling one or a plurality of units in a lamp housing.
2. Description of the Related Art
FIGS. 1A and 1B show a projector type vehicle headlamp unit 100 (Japanese Patent Application Laid-open No. 2003-229006). This unit 100 is provided to solve problems in that the LED as the light source has high intensity and looks like arrangement of spots, a reflecting surface does not reflect light beautifully, and the LED cannot form a large light-emitting surface. The unit 100 includes an LED 1 mounted on a printed circuit board 104, a first reflecting member 101 arranged so as to surround the front of the LED 1, a second reflecting member 102 arranged opposite to the reflecting member 101, and a light distribution control lens 103 arranged in front of the second reflecting member 102. A reflection coating 101a of the first reflecting member 101 is formed by rotating a part of an elliptical curved surface having a first focal position F1 located near a light-emitting section 1a of the LED 1 and a second focal position F2 located away from an optical axis Z and obliquely forward from the light-emitting section 1a of the LED 1, in the shown example. In FIG. 1B, reference numeral 105 denotes a translucent cover.
According to the unit 100, at the time of lighting the LED 1, the light thereof is reflected by the reflection coating 101a of the first reflecting member 101, converges on the second focal position F2, and the light converged on the second focal position F2 is reflected by the reflection coating 102a of the second reflecting member 102, and proceeds forward as parallel beams. The parallel beams enter into the light distribution control lens 103, and is aimed and light distribution of the beam is controlled. Accordingly, the parallel beams are irradiated forward, to achieve the initial object. In FIG. 1A, the emission part is shown by hatching lines.
However, the unit 100 has a problem in that since a non-emission part appears in the middle of the light-emitting surface (see FIG. 1A), the suitability as the vehicle headlamp is not sufficient.
Since the unit 100 is for constituting one headlamp unit by one LED, color irregularity at the time of lighting the LED appears by 100%, thereby causing deterioration in the appearance at the time of lighting the LED.
Furthermore, since the unit 100 is for constituting one headlamp unit by one LED, if a plurality of LEDs are to be installed due to insufficient illuminance, the unit 100 must be installed corresponding to the number of LEDs, thereby causing a problem in which the entire headlamp becomes large.